"There is no Salvation outside the Roman Catholic Church"
I think an explanation is an order, as some, perhaps even some Catholics, take the above literally that one must be enrolled in the Catholic Church, or they will burn in hell. This is just not true, nor was it ever! Even the Church Fathers themselves declared that some of the Greek philosophers predating Christianity were "Christians" in their thought. I would like to quote Father Most, as he explains the Church's teachings very well.
"From the fact that the Church is God's means of giving grace, is it is clear that there is no salvation outside the Catholic Church. This truth has even been defined by the Church more than once, e.g., in the Council of Florence in 1442. However we must take care to understand this teaching the way the Church understands it. One like Leonard Feeney, who interprets the teaching on the necessity of the Church his own way is not acting like a Catholic theologian at all. The Holy Office, on August 8, 1949, declared that L. Feeney was guilty of this error. Because of his error, he rejected several teachings of the Magisterium, saying they clashed with this definition - but they clash only with his false interpretation, given in private judgment.
Pius IX (Quanto conficiamur moerore, August 10, 1863) taught: "God... in His supreme goodness and clemency, by no means allows anyone to be punished with eternal punishments who does not have the guilt of voluntary fault." Vatican II (Lumen gentium # 16) taught the same: "They who without their own fault do not know of the Gospel of Christ and His Church, but yet seek God with sincere heart, and try, under the influence of grace, to carry out His will in practice, known to them through the dictate of conscience, can attain eternal salvation." Pius XII had said (Mystici Corporis Christi) that one can "be related to the Church by a certain desire and wish of which he is not aware", i.e., by the desire to do what God wills in general.
Precisely how does this work out? St. Paul insists (Romans 3:29) that God makes provision in some way for all. One of the earliest Fathers, St. Justin Martyr (Apology 1:46) said that some, like Socrates could even be Christians because they followed the divine Word. Now St. Justin also said that the Divine Word is in the hearts of all. Then we notice in St. Paul's Romans 2:14-16 that "The gentiles who do not have the law [revealed religion] do by nature the things of the law; they show the work of the law written on their hearts." And according to their response, they will or will not be saved.
Clearly, it is this Divine Word, or the Spirit of Christ, the Divine Word, that writes the law on their hearts, i.e., makes known to them what they should do. If they follow that, although they do not know that that is what they are following, yet objectively, they do follow the Logos, the divine Word. And so St. Justin was right in calling them Christians. We can add that St. Paul in Romans 8:9 makes clear that if one has and follows the Spirit of Christ, he "belongs to Christ." But, to belong to Christ is the same as being a member of Christ, and that is the same as being a member of the Church. Not indeed by formal adherence, but yet substantially, enough to satisfy the requirement of substantial membership. Indeed, Vatican II even wrote (LG # 49): "All who belong to Christ, having His Spirit, coalesce into one Church."
So, St. Paul was right: God does take care of them; St. Justin was right too: they can be Christians without knowing it. Otherwise, God would be sending millions upon millions to hell without giving them any chance at all, if they lived far from places where the Church was known, e.g., in the western hemisphere before 1492.
That fact that salvation is possible in this way does not mean that there should be no missions or attempts to bring back the Protestants. Richer and more secure means of salvation are to be had with formal explicit adherence to the Catholic Church. Therefore we need to make every effort. In regard to Ecumenism, it is good to keep in mind a rule from Vatican II, in its Decree on Ecumenism (# 11): "It is altogether necessary that the complete doctrine be clearly presented. Nothing is so foreign to true Ecumenism as that false peace-making in which the purity of Catholic doctrine suffers loss, and its true and certain sense is obscured."
I hope this clarifies the Church's teachings on the subject. One can be a "Catholic" and not even realize it. One can be considered a catholic in the sense that they follow the teachings of the Apostles, as given to them by Christ. One who follows the Law of Love, but know not who instituted it, can still be considered "catholic" in the sense that they are somehow a part of the Church. They are following the Law written on their hearts by God. Invincible ignorance will not be a reason for a soul to endure eternal punishment. Adamant refusal to enter Christ's Church, when one knows what it is, however, faces the distinct possibility of being refused by Christ entry into the Kingdom of Heaven.
Regards
Give them the smallest peg, or what appears so, not to you, but to them;- the smallest peg, on which to hang a hope of salvation without being in or actually reconciled to the church by the sacrament of penance,- and all the arguments you can address to them to prove the necessity of being in the church in order to be saved, will have no more effect on them than rain on a duck’s back. You may bring them in the church for aesthetic reasons, by the grandeur and pomp of your liturgy, your taste in church decoration, your solemn and soul-entrancing music, even for intellectual reasons, but never as the necessary means of saving their souls. St. Augustine wrote his “Confessions,” but not usually do those converts write the history of their conversion, who were led to the church by the need they felt of getting rid of their sins, and of supernatural grace to assist them to lead an upright spiritual life. ... There can be no more fatal mistake than to soften, liberalize, or latitudinize this terrible dogma, “Out of the church there is no salvation,” or to give a man an oppurtunity to persuade himself that he belongs to the soul of the church, though an alien from the body.
Fr. Feeney never had to recant his position through all of the persecution he endured.
Any idea of "anonymous Christianity" is pure speculation. And ultimately it undermines the teachign of the Church.
There is not one dogmatic statement that indicates that Baptism of Desire or Baptism of Blood conveys the same character as Baptism of Water and Spirit. We hope for it in our weak and imperfect personal faith and understanding but nothing like that is part of revealed doctrine.
Millions and millions do go to Hell is the Catholic teaching. The way is narrow, many are invited and few get in.
Aquinas states two things, That even a just man with grace will fall into mortal sin. And secondly if someone has no access to Christ and still seeks him honestly, that God will send an Angel to minister to him. Whether that happens to our Protestant, Orthodox and Jewish, Muslim and Pagan friends in the time between the last second of life and the first second of death is known only to God, that person and the Spirits involved.
All of the citations used by Fr. Most can be addressed more accurately with an understanding of EENS that is consistent with the more direct statements by the Holy See. Fr. Most neglects to quote the Council of Florence but rather just alludes to it. I suspect he does this because it flies in the face of much of what he writes.
"[The most Holy Roman Church] firmly believes, professes, and proclaims that those not living within the Catholic Church, not only pagans, but also Jews and heretics and schismatics cannot become participants in eternal life, but will depart `into everlasting fire which was prepared for the devil and his angels' (Matt. 25:41), unless before the end of life the same have been added to the flock; and that the unity of the ecclesiastical body is so strong that only to those remaining in it are the sacraments of the Church of benefit for salvation, and do fastings, almsgiving, and other functions of piety and exercises of Christian service produce eternal reward, and that no one, whatever almsgiving he has practiced, even if he has shed blood for the name of Christ, can be saved, unless he has remained in the bosom and unity of the Catholic Church."
Ignorance and good feelings and intentions are simply not enough and they are not equal to Christ's dying on the Cross, establishing his Church and giving us the Sacraments to enable us to participate in his gift of salvation.
God is the just Judge. Trust in him. We don't have to add to the deposit of Faith in order to make ourselves feel better. As Gerry Matatics said to me one time when referring to his daughter who died in childbirth (he baptized her immediately) "But if I was too late and if I'm graced enough to get to Heaven, if I don't see my daughter there, I'm not going to cross my arms and tell God that 'Hey! Something's wrong up here!"